well I really wanted a Monster... I almost got one!

buzzer · October 23, 2018, 02:34:05 AM

on a monster with carbs, the side of each carb there is a pipe that vents to the plastic box on the side. Question is, do they vent to a box each side, or just one box?

I am converting a Multistrada to carbs so have no bike to reference to!

ducpainter · October 23, 2018, 04:00:58 AM

On a stock bike they go to a 'pod' on each side.

It doesn't matter, as long as those hoses are in still air. If air flows across the end of the pipe, the diaphragms won't work correctly.

buzzer · October 23, 2018, 05:00:40 AM

Quote from: ducpainter on October 23, 2018, 04:00:58 AM
On a stock bike they go to a 'pod' on each side.

It doesn't matter, as long as those hoses are in still air. If air flows across the end of the pipe, the diaphragms won't work correctly.

thanks, do you think it would be ok to feed them into a single "pod" rather than two?

ducpainter · October 23, 2018, 05:07:54 AM

On my bike the hoses are just routed up behind the battery. The hoses don't 'have' to be enclosed, as long as the air is still.

One 'pod' should be fine.

You're using BDST carbs for this project? Most use flatslides.

koko64 · October 23, 2018, 05:12:07 AM

Are you running pod filters or an airbox? The hoses shelter easily behind an airbox or battery box but it's more difficult to find a calm space with pod style air filters. With pod style filters you could affix some of those breather pods to the battery box and run the hoses that way. Note that the central breather runs to one pod and the baffled breathers (with small canisters) share a common pod.
You should tell us more about your Multi/carb conversion

I think it's worth a write up in the mods section.

greenmonster · October 23, 2018, 06:42:45 AM

https://jtccc.wordpress.com/our-motorbikes/ducati-multistrada/

Don`t think I`ve seen 1kDS converted to BDST, anyone else has?

buzzer · October 23, 2018, 11:19:44 AM

Quote from: greenmonster on October 23, 2018, 06:42:45 AM
https://jtccc.wordpress.com/our-motorbikes/ducati-multistrada/

Don`t think I`ve seen 1kDS converted to BDST, anyone else has?

Thanks for the link... it remains to be seen how well it runs... cost was a consideration, the flat slides are expensive... I managed to pick up son Mikuni carbs for Â£35 with seized air screws, but managed to free them off OK!

koko64 · October 23, 2018, 12:29:41 PM

Thanks for the link Gert

. That was an enjoyable read.

Welcome Buzzer. I liked how you went your own way and damn the rest

. What a great build with no stone unturned.

From digital to analogue

If those carbs don't meet the engines needs they can be bored and taper bored/ported. I don't know the maximum bore possible but I'm guessing 40ish. Those oem carbs struggle to give a modified 900 what it needs and when it needs it. I can't see why you couldn't build an uber carb at 41-42mm. I would enjoy watching you do it

. Maybe Honda VTR1000 carbs could be modified to fit your manifolds.

koko64 · October 23, 2018, 01:18:40 PM

Quote from: greenmonster on October 23, 2018, 06:42:45 AM
https://jtccc.wordpress.com/our-motorbikes/ducati-multistrada/

Don`t think I`ve seen 1kDS converted to BDST, anyone else has?

Never afaik.
The carbs are underwhelming in stock form, but Doug Lofgren has made them work with extensively modified, ported, hi comp 900 Monster engines bored up to 985.

I would like to see Buzzer build a BDST uber carb

.

buzzer · October 24, 2018, 12:56:54 AM

Quote from: koko64 on October 23, 2018, 12:29:41 PM
Thanks for the link Gert . That was an enjoyable read.

Welcome Buzzer. I liked how you went your own way and damn the rest . What a great build with no stone unturned.

From digital to analogue

If those carbs don't meet the engines needs they can be bored and taper bored/ported. I don't know the maximum bore possible but I'm guessing 40ish. Those oem carbs struggle to give a modified 900 what it needs and when it needs it. I can't see why you couldn't build an uber carb at 41-42mm. I would enjoy watching you do it . Maybe Honda VTR1000 carbs could be modified to fit your manifolds.

Thanks for that! I never thought of using the carbs off the Honda... they look to be 48mm which is pretty big, and they are cheap on Ebay! looking at them they would fit if I made some different manifolds, and I do have a length of pipe left over from the Mikuni ones I made... its something to consider...

can anyone think of any other bike of around 500cc per cylinder that used carbs?

koko64 · October 24, 2018, 04:02:29 AM

What size carbs did the Honda Varadero (or whatever its called) have? Maybe they are a little smaller and more suitable.

greenmonster · October 24, 2018, 06:08:33 AM

My SR500 had 34 mm Mikuni stock.
Overbore to 526 & Supertrapp full system, 38 mm Mikuni VM was better.
Many Harleys work fine w one 38 mm Keihin vacuum slide carbs.

Speeddog · October 24, 2018, 09:55:34 AM

My Yamaha XV920R had a pair of 40mm Hitachi CVs.
Note, that engine was essentially a pair of SR500 top ends on a single crankcase.

Lessee, roundabout 500cc 2-valve air-cooled with regular slide carb?
36 is on the large end of what my (dodgy) memory tells me.

buzzer · October 25, 2018, 12:30:19 AM

Well it looks like the Varadero carbs are 42mm.... i must say i am tempted to buy a pair! I will think about it... There has been a bit more progress over the last few days...I have mounted the battery under the tank, and put the coils and solenoid on the battery box, which is rubber mounted on four grommets to insulate it from vibration. I have finished off the mudguard mountings, and also the mounting to support the exhaust.

the silencer has been a pain.. I bought it off Ebay new, the seller described it as stainless steel. when it came, it looked good, so I stripped it apart and chucked the cone into some thinners... this stripped all the paint off. a this point I suspected it was mild steel, turns out it is! so for now, I have painted it with silver VHT paint and it looks OK. I may decide to have it chrome, or even black. the seller was very understanding and refunded my Â£21! thought it was cheap!

I was going to mount the fuel tap which I have bought (its fitted to a Suzuki 1000 Bandit) but there is not enough room for it, so I will have to think again... I want a tap with a reserve if I can...

I have now started mounting the electrical components and will soon start the the wiring, a job which I quite enjoy. just got to mount the headlight first...

koko64 · October 25, 2018, 03:49:57 AM

From tourer to hot rod

So you met the ignition requirements with an Ignitech. Did you use a supplied or custom map? What initial setting you use in the programme?

Looks a lot easier to work on than the Multi 1100 I have stripped down in the workshop.

News:

well I really wanted a Monster... I almost got one!